The present invention relates to a communication network system, and more particularly to an application program execution control in a switching system in which a switchboard and a computer to provide services to subscribers are connected so that the software of the switchboard and the software of the computer cooperate with each other to execute the services to subscribers.
J. Shah, et al, "Application of a New Network Concept for Faster Service Deployment" CH25387/88/0000, 1988, pp. 1327-1331 and J. Rix-Broun, "The Telephone and the Terminal on Your Desk Join Forces", 1989, pp. 331-341 have disclosed a PBX system which is connected with a computer.
In regard to the conventional switching system of a type in which a switchboard and a computer are controlled by software of the switchboard and the software of the computer cooperating with each other to execute services, Proceedings of the Institute of Electronics, Information and Communication Engineers of Japan, SB-4-1, Autumn National Conference, 1989 has proposed a system which is constructed with 5 switchboards and m computers; and, in which the switchboards manage which computer executes individual application programs are executed upon generation of a request from a subscriber, and a switchboard determines a computer to be associated with the switchboard to control the corresponding application program and entrusts the determined computer with the control (proposal 1). This reference has further proposed a system in which the correspondence between individual application programs and computers to execute the application programs is managed by a specified computer and upon generation of a request from a subscriber the specified computer determines, through access from a switchboard, a computer to be associated with the switchboard to execute the corresponding application program and entrusts the determined computer with the control (proposal 2-1) and a system in which, upon generation of a request from a subscriber, a switchboard makes a reference to the specified computer in the proposal 2-1 to determine a computer to be associated with the switchboard to execute the corresponding application program and entrusts the determined computer with the control (proposal 2-b).
Also, JP-A-1-157192 has disclosed a system having a construction in which a plurality of computers are connected with one switchboard and a processor of the switchboard is provided with an application management section. The application management section analyzes or determines which of the computers is to execute an application the start of which is requested from a subscriber, and a start request is sent from the application management section to the determined computer. This system is basically similar to the system mentioned in the above proposal 1.
JP-A-157191 has disclosed a measure to counter the case where a circuit line connected to a subscriber terminal is disconnected during execution of a service by the cooperation of a switchboard and a computer, that is, a system in which a processor of the computer is provided with an application management section for storing the application number of an application under execution in a form corresponding to the terminal number of a subscriber terminal, so that, upon disconnection of a circuit line, the application management section terminates the execution of a portion of the relevant application for the corresponding subscriber.